1. Technical Field
This invention relates to a power conversion apparatus.
2. Related Art
A known power conversion apparatus includes a motor-generator control apparatus as disclosed in Japanese Patent Application Laid-Open Publication No. 2011-083179.
The disclosed motor-generator control apparatus includes a power supply circuit that supplies a voltage for driving each of a plurality of insulated gate bipolar transistors (IGBTs) to a drive circuit for the IGBT. The power supply circuit includes a transformer, a switching element (MOSFET: metal-oxide-semiconductor field-effect transistor), a plurality of rectification circuits (diodes), a plurality of capacitors, and a control circuit (an output voltage stabilization circuit). The transformer includes a primary coil and a plurality of secondary coils. One of the plurality of secondary coils (a feedback secondary coil) is used for feedback of an output voltage of the transformer to the control circuit and each of the other secondary coils is used to supply a voltage to a respectively corresponding drive circuit. One of a pair of terminals of the primary coil is electrically connected to the switching element and the other of the pair of terminals of the primary coil is electrically connected to a low-voltage battery. A direct-current (DC) voltage supplied from the low-voltage battery is converted into an alternating-current (AC) voltage by alternately turning on and off the switching element. The AC voltage is supplied to the primary coil. One of the rectification circuits, which is electrically connected to the feedback secondary coil, rectifies an AC voltage outputted from the feedback secondary coil into a DC voltage to feed back the DC voltage to the control circuit. Each of the other rectification circuits associated with the respective secondary coils other than the feedback secondary coil is used to supply a DC voltage to a respectively corresponding drive circuit. The plurality of capacitors are electrically connected to the respective rectification circuits. Each of the plurality of capacitors smooths a DC voltage from a respectively corresponding rectification circuit. The control circuit is electrically connected to the feedback rectification circuit and to the switching element, and controls the switching element in response to the DC voltage rectified by the feedback rectification circuit. That is, the control circuit controls the switching element so that the DC voltage rectified by the feedback rectification circuit is kept at a predetermined voltage. This allows an output voltage of each of the other rectification circuits, that is, each output voltage of the power supply circuit, to be stabilized at a predetermined voltage.
In the disclosed motor-generator control apparatus, however, the transformer, the switching element, the feedback rectification circuit, the capacitor for the feedback rectification circuit, and the control circuit are mounted on a wiring board. A pulse signal for turning on and off or switching the switching element is transmitted through a wiring pattern that connects the control circuit and the switching element. When a wiring pattern that connects the feedback rectification circuit and the control circuit crosses the wiring pattern that connects the control circuit and the switching element, noise associated with the pulse signal will be superimposed on a signal transmitted through the wiring pattern that connects the feedback rectification circuit and the control circuit. This may prevent the switching element from being controlled properly on the basis of the DC voltage rectified by the feedback rectification circuit, which may thus prevent the output voltages of the power supply circuit from being stabilized.
In consideration of the foregoing, exemplary embodiments of the present invention are directed to providing a power conversion apparatus capable of preventing a wiring pattern that connects a feedback rectification circuit and a control circuit and a wiring pattern that connects the control circuit and a switching element controlled by the control circuit from crossing each other, thereby suppressing adverse effects of noise.